ABSTRACT
The turfgrasses are usually grouped into cool season (Festucoideae) and warm season (Erogrostoideae, Panicoideae) categories. Although this grouping is made primarily for climatic adaptation for turf use, species in the two groups generally differ in their requirements for flowering. 2 The cool-season turfgrasses are mostly long-day plants while the warm- season are predominantly short-day or day neutral. Many of the cool-season turfgrasses also have a vernalization requirement but a true vernalization response is unknown among the warm-season plants. 6
